package com.jlsoft.config.oauth.handler;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.jlsoft.config.SimpleResponse;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.security.authentication.BadCredentialsException;
import org.springframework.security.core.Authentication;
import org.springframework.security.crypto.codec.Base64;
import org.springframework.security.oauth2.common.OAuth2AccessToken;
import org.springframework.security.oauth2.common.exceptions.UnapprovedClientAuthenticationException;
import org.springframework.security.oauth2.provider.*;
import org.springframework.security.oauth2.provider.token.AuthorizationServerTokenServices;
import org.springframework.security.web.authentication.SavedRequestAwareAuthenticationSuccessHandler;
import org.springframework.security.web.savedrequest.HttpSessionRequestCache;
import org.springframework.security.web.savedrequest.RequestCache;
import org.springframework.stereotype.Component;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

@SuppressWarnings("all")
@Component
@Slf4j
public class BrowerAuthenticationSuccessHandler extends SavedRequestAwareAuthenticationSuccessHandler {

    @Autowired
    private ClientDetailsService clientDetailsService;

    @Autowired
    private AuthorizationServerTokenServices authorizationServerTokenServices;

    @Autowired
    private ObjectMapper objectMapper;

    private RequestCache requestCache = new HttpSessionRequestCache();


    @Override
    public void onAuthenticationSuccess(HttpServletRequest request, HttpServletResponse response, Authentication authentication) throws IOException, ServletException {

        String header = request.getHeader("Authorization");

        if (header == null || !header.startsWith("Basic ")) {
            throw new UnapprovedClientAuthenticationException("请求头中无client信息");
        }

        //base64 解码 [用户名,密码]
        String[] tokens = extractAndDecodeHeader(header, request);
        assert tokens.length == 2;

        String clientId = tokens[0];
        String clientSecret = tokens[1];

        ClientDetails clientDetails = clientDetailsService.loadClientByClientId(clientId);

        if (null == clientDetails) {
            throw new UnapprovedClientAuthenticationException("clientId对应的配置信息不存在:clientId:"+clientId);
        }
        else if (!clientDetails.getClientSecret().equals(clientSecret)) {
            throw new UnapprovedClientAuthenticationException("clientSecret不匹配："+clientId);
        }

        Map emptyMap = new HashMap();

        TokenRequest tokenRequest = new TokenRequest(emptyMap, clientId, clientDetails.getScope(),
                                    "custom");


        OAuth2Request oAuth2Request = tokenRequest.createOAuth2Request(clientDetails);

        OAuth2Authentication oAuth2Authentication = new OAuth2Authentication(oAuth2Request, authentication);

        OAuth2AccessToken oAuth2AccessToken = authorizationServerTokenServices.createAccessToken(oAuth2Authentication);

        log.debug("登录成功...");

        response.setStatus(HttpStatus.OK.value());
        response.setContentType("application/json;charset=UTF-8" );
        response.getWriter().write(objectMapper.writeValueAsString(
                new SimpleResponse(0,
                        //JSON.toJSONString
                                (oAuth2AccessToken), true)
        ));
    }


    /**
     * Decodes the header into a username and password.
     *
     * @throws BadCredentialsException if the Basic header is not present or is not valid
     * Base64
     */
    private String[] extractAndDecodeHeader(String header, HttpServletRequest request)
            throws IOException {

        byte[] base64Token = header.substring(6).getBytes("UTF-8");
        byte[] decoded;
        try {
            decoded = Base64.decode(base64Token);
        }
        catch (IllegalArgumentException e) {
            throw new BadCredentialsException(
                    "Failed to decode basic authentication token");
        }

        String token = new String(decoded, "UTF-8");

        int delim = token.indexOf(":");

        if (delim == -1) {
            throw new BadCredentialsException("Invalid basic authentication token");
        }
        return new String[] { token.substring(0, delim), token.substring(delim + 1) };
    }
}
